PreSage-MS: Metric Spaces in PreSage

We consider adaptation in open systems, i.e. systems without global objects or common objectives. There are three related issues: how to make the degrees of freedom (DoFs) transparent to all agents, how to define a `fair' process for performing adaptation, and how to retain some control over the adaptation to avoid, for example, undesirable configurations. We represent the specification DoFs in terms of a metric space, and define, in a uniform and consistent way, a mechanism for `moving' between points in the metric space which is both `fair' to the agents and avoids unacceptable moves or points in the space. This approach is demonstrated by the platform PreSage-MS, which allows a designer to specify and animate an adaptive open multi-agent system in terms of a metric space and norm-governed rules for `moving' in that space.